1. Field Of The Invention
The present invention relates to a motor control circuit used for applications such as the driving device for a power window or sun-roof in a car, which cuts off the power to the motor when the motor is mechanically stopped while the control switch continues to be switched on.
2. Description Of The Background Art
There has been strong desire in the past to have a single control switch, which alone can open the sun-roof and all windows to quickly ventilate the air inside a car when the driver enters the car during the summer season. Also, there has been desire, for the convenience of the users, to have a single control switch, which can totally close the sun-roof and all windows when the driver exists the car.
However, when the sun-roof and all windows are totally opened or totally closed by a single control switch, two or more motors must be simultaneously operated. If there is a difference in the time to totally open or totally close the windows according to the differences in the opening and closing strokes or to the difference in the speeds of all the different motors, it is necessary to continue to operate the control switch until the last sun-roof or window reaches the desired limit of its operation. During this time, the other motors are already at the upper limit or lower limit of their operation and are locked. Even when the motors are in a locked condition, electric current continues to flow and power is wasted for no purpose. Also, the durability and life of the motor are reduced by heating or burn-out.